1. Technical Field
The subject matter of the present disclosure relates to lighting devices and, more particularly, to the use of lighting modules comprising light emitting diodes (LEDs) for constructing lighting devices.
2. Description of Related Art
Use of fluorescent and incandescent light fixtures is common. These light fixtures are found in residential and commercial premises, often in the form of large, panel-like fixtures (e.g., fluorescent fixtures) or recessed, can-like fixtures (e.g., incandescent and compact-fluorescent fixtures). Panel-like fixtures typically comprise a housing with one or more fluorescent bulbs or “tubes.” A diffuser panel covers the bulbs. The diffuser panel comprises a translucent or transparent material, with or without surface patterning, that promotes uniform emission of light through the light emitting surface of the fixture and into the lighted space.
Panel-like fixtures and can-like fixtures are likely found in suspended (“drop”) ceilings. These ceilings include a grid of support members in combination with cables or tie members that hang the grid from the ceiling. Panels and tiles populate the openings in the grid. In one construction, one or more light fixtures also fit within the openings (or within the tiles themselves) to replace or supplement certain ones of the tiles. This arrangement maintains the look and continuity of the ceiling.
In addition to fluorescent and incandescent technology, new generations of lighting fixtures an array of light emitting diodes (LEDs) to generate light. LEDs offer many advantages over their fluorescent and incandescent counterparts. These advantages include, for example, much higher efficiency and longer operating lifetimes, potentially on the order of 100,000 hours or more. Moreover, the compact size of LEDs reduces the overall dimensions (e.g., thickness) of the resulting lighting fixture. For example, thin and ultra-thin designs for LED-based lighting fixtures and panels place LEDs about the periphery of the fixture to form an “edge-lit” lighting fixture as opposed to the traditional “back-lit” lighting fixture in which LEDs (or fluorescent bulbs) are dispersed perpendicular to the light emitting surface of the fixture.
As discussed above, edge-lit lighting fixtures include an array of LEDs, as well as a power supply and a light guide that disperses light from the edges of the fixture to uniformly light the light emitting surface. For many applications, the LEDs couple in series, thus the number of LEDs determines the size, shape, and other requirements for the power supply.